Lipoprotein(a) is a lipoprotein particle with a similar structure to low density lipoprotein (LDL). In Caucasian and Oriental populations, high levels of Lp(a) are associated with an increased risk for atherosclerosis and blood clotting problems. This study is to determine how Lp(a) may interfere with the process of dissolving blood clots, using plasma from normal volunteers to purify the Lp(a).